This study uses the World Health Organization’s AirQ+ model to assess the relationship between air pollution and mortality in Portugal from 2010 to 2021, focusing on the impact of the COVID-19 pandemic. By integrating AirQ+ with Linear Mixed Models, we analyzed long-term air pollution data and its health effects. Results indicate a significant decrease in \({\text{NO}}_{2}\) and \({\text{PM}}_{2.5}\) concentrations in 2020 and 2021 due to COVID-19 restrictions and reduced transportation emissions. Conversely, \({\text{O}}_{3}\) exposure slightly increased. The model estimates over 5000 annual deaths from \({\text{NO}}_{2}\) and \({\text{PM}}_{2.5}\) exposure and over 139 annual deaths from \({\text{O}}_{3}\) -related respiratory diseases for 2010–2021. Despite limitations like the need for better assessment of pollutant mixtures and climatic variables, the study shows a decrease in \({\text{NO}}_{2}\) -related disease burden during the pandemic. These trends reflect anomalies in mortality and pollution data rather than policy improvements. The study underscores the utility of AirQ+ in guiding public health strategies and tracking progress toward the 2030 Agenda, offering insights into reducing mortality and morbidity through decreased air pollutant exposure and highlighting the need for sustained, multidimensional pollution reduction efforts.
